I want to ask how I can divide feature extraction techniques to feature detectors and feature descriptors. I have big problem how to understand it. For example I can use Gabor filters (feature detector) to extract phase information (so the phase is feature) about image and then process this information to binary information like Daugman (I dont know if this is feature descriptor). I dont understand others approaches like Laplacion of Gaussian, SIFT, PCA, DCT and etc. Thanks for answer.